EMCrit Podcast 172c – Vent as Bag & VAPOX

VAPOX and Vent-as-Bag

In a concept piece called Preoxygenation. Reoxygenation and Delayed Sequence Intubation in the Emergency Department, I outlined a concept which I called: the vent as a bag. Why would we use the unpredictable and unmeasured BVM, when instead we could use a purpose-built, strictly internally regulated machine like a ventilator. I had stopped talking about the idea when numerous people told me it was unfeasible in their environment–however, I continued this practice for my own patients throughout my practice.

Recently, Grant et al. published a case series using the same concept–they have dubbed their vision of it VAPOX.

One thing I do and have seen done by many, is place a Nasal Trumpet (lubed with lidocaine jelly), then take the end off of a 7.0 ETT, attaching it to the trumpet, This can then be connected to the circuit and patient placed on the vent at settings similar to those in the VAPOX protocol. When doing anesthesia in a remote setting without a vent, it easily attaches to a BVM.

I personally, feel this may be a little more tolerable than a mask, plus it aids in maintaining a patent airway in the patient that may obstruct. Additionally, if intubation is needed, you can continue to provide apneic oxygenation.

I have seen this as well and even the dual nasal trumpet connectors. A very workable solution.

Vote Up0Vote Down Reply

2 years ago

Guest

Ryan

Too difficult? Too complex? Really?

No. It’s just laziness. Learn the vent, learn from an RT, get equipment staged in the ED…. Do what you have to do to be good to the patient.

Using the vent as a bag is safe, and smart. It also frees up cognitive loading as you don’t need to constantly worry about the BVM being perfectly done.

Vote Up0Vote Down Reply

2 years ago

Guest

Greg

Hello, ED RT here;

I’ve been use this technique sporadically in our ED. Works great in high stress situations so other logistics of the intubation can be prepared for. Personally I use AC with low flows, instead of SIMV. On our ED vents, in addition to the normal macro parameters measured (vt, ve, PIP) I also show leak in LPM. 20-50 is target max for leak compensation

Bravo! This techniques extends to the prehospital environment as well. Lee County Department of Public Safety/EMS has dramatically reduced dependency on bag-mask ventilation in favor of using a SIMV transport ventilator for most, if not all, conditions that require ventilation. For all the patient safety reasons that you have identified, this paradigm shift has proved to be very successful in reducing provider variability.

Vote Up0Vote Down Reply

2 years ago

Guest

Evan

I’m curious, for this particular use, would pressure control be a preferable mode to avoid opening of the lower esophageal sphincter? You could set P_h to 20cmH2O for example, as I worry with a more leaky system you might reach higher peak pressures with a volume control mode as the vent attempts to deliver the set volume. I suppose using 30L/m flow rate is to help minimize that effect. As you said, the primary goal is oxygenation in this patient, which is well accomplished with PC as well.

Also, are you suggesting this can be a hands free operation once the mask is strapped? When I’ve ventilated patients in the OR after pushing the paralytic, I almost always had to apply a jaw thrust or chin tilt to open the airway or utilize an OPA. If they are in the Fowler’s position (with gravity to help), or are not paralyzed then I can see this being truly hands free.

I will see if I can convince my attending to let me try this technique for my next intubation as my nursing staff looks on in bewilderment.

you still need the manual jaw thrust after you push the meds. straps only keep you from having to hold during 3 minute preox. PC works fine as well.

Vote Up0Vote Down Reply

2 years ago

Guest

Anu Mascarenhas

HI I am a ED registrar working in perth. Just listened to this podcast today. I liked the idea of using the vent to pre oxygenate but two questions came to mind. First of all am presuming that you can deliver higher FIO2 using the vent instead of a bag mask? Also usually we do not bag while the patient is apneic, so if you had a your vent set to 8 bpm then during the apneic period you will still be delivering breaths. Does that not incerase your risk of gastric insufflation and thereby incease vomitting?

I love this paper and this concept. To address a certain patient scenario- if you had a super tachypenic patient with salicylate OD or DKA would you alter the rate on the vent to something above 6-8 breaths per minute during the apneic period in order to maintain that respiratory compensation? Do you think there would be any benefit to doing this and would it be safe?

thanks Scott. this idea of VAPOX has intrigued me since the paper came out . Its true that after your mentioned it in your early podcast, it fell out of focus and no one really talked about it till now. My own interest has been fuelled by issue in prehospital care of using multiple oxygen sources for RSI preox and NIPPV in general. As well recent papers have questioned the benefit of Nasal ApoX and I must admit my thinking on this has changed as well, particularly in prehospital care WE have to carry our own oxygen with us to scenes if we want to do RSI etc. This is usually limited in my service to 2 x 630litre cylinders called CD size. I have to reinforce here that sometimes our travel distance to the scene maybe several kilometres from aircraft ( its a fixed wing so we dont always land where the patient is!) so imagine having total of 1260 litres of oxygen on scene, its just you and your nurse and no other emergency crews are there or can get there due to remoteness. Typically what has been described in the EM blogs and literature in the last… Read more »

yep-not a limitation I have. If you use VAPOX with breaths during apnea, no gain or need for apneic ox or NC for preox. Would strongly recommend you get some mask straps–makes the preox much easier.

Vote Up0Vote Down Reply

2 years ago

Guest

William Kimbrell

Billy Lifeguard 1 flight nurse. I also worry about risk for vomiting during the apox period. Could you educate me more about this. I really appreciate your podcast btw. It is used in large part as our training source with our Helicopter EMS service! It has changed how I think about medicine and airway management. Keep up the good work!

A concern is that the Oxylog 3000plus has alarms off in NIV – compensates well for leak but no alarms.
The paper in JEMAustralasia used Hamilton ventilators which may be different.
Would waveform capnography be enough, to add to alertness, to stay safe with this technique?